1. Field
The present teachings relate to a rechargeable battery.
2. Description of the Related Art
Batteries perform electrochemical redox reactions to produce electrical energy from chemical energy. Batteries can be classified as a primary battery, which is not rechargeable, or as a secondary battery, which can be recharged.
Recent developments in the high-tech electronics industry has lead to the proliferation of portable electronic devices. As a power source for such portable electronic devices, much research has been directed to developing high energy density lithium rechargeable batteries.
A lithium rechargeable battery includes a battery cell provided with a positive electrode and a negative electrode, and a battery case to house the battery cell. The battery may be classified as cylindrical, polygonal, or pouch-type, according to the shape of its case. Pouch-type rechargeable batteries have a lower surface and an upper surface, which are sealed together around the battery cell. Pouch-type batteries generally have a lighter weight than cylindrical or polygonal batteries.
In case of a pouch-type rechargeable battery, water may permeate the interface between the lower surface and the upper surface of the case. If water permeates into a battery, the reliability of the battery cell may be degraded.